Dyeable polyolefin bulk textile fibers and process for their preparation



March 1970 F. BERTINOTTI ET AL 3,

DYEABLE POLYOLEFIN BULK TEXTILE FIBERS AND PROCESS FOR THEIR PREPARATION Filed May 11, 1967 United States Patent O US. Cl. 161-169 12 Claims ABSTRACT OF THE DISCLOSURE Dye-receptive synthetic high bulk textile fibers obtained by blending drawn and crimped dye-receptive staple fibers comprising a polyolefin consisting at least prevailingly (over 50%) of isotactic macromolecules and from about l-25% by weight of said polyolefin of an epichlorohydrin-amine polycondensate, from to 90 percent of these fibers having been subjected to a thermal stabilization treatment at a temperature of about 100l50 C. after drawing and crimping and, correspondingly, from about 90 to 10% of the fibers being unstabilized to heat, having been exposed to temperatures not higher than about 50 C. after drawing and crimping, spinning the resulting blend and then subjected it to a thermal treatment at a temperature of from about 100-140" C. Shrinkage of the unstabilized portion of the blend upon thermal treatment of the blend causes the bulking of the fibers.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to bulk textile fibers of dyeable polyolefins and to a process for their preparation.

Description of the prior art Processes for the preparation of polyolefin fibers which are receptive to acid dyes are described in US. Patent applications 124,346, filed July 17, 196-1, now abandoned; 212,119 filed July 24, 1962, now abandoned 506,016, filed Nov. 1, 1965; 548,388, filed May 9, 1966, now US. Patent 3,454,670; and in Italian patents 661,481 and 735,202. In accordance with the disclosures of these patents and patent applications, the modification is obtained by addition to the polyolefins of polycondensation products of epichlorohydrin with amine compounds. Suitable polycondensates are for example:

epichlorohydrin n-octodecylamine/ hex amethylenediamine,

epichlorohydrin /n-octodecylamine/piperazine,

epichlorohydrin/n-dodecylamine/piperazine,

epichlorohydrin /piperazine,

epichlorohydrin/ pi perazine dicyclohexylhexamethylenediamine,

epichlorohydrin /hexarnethylenediamine/alkyl halide,

epichlorohydrin /n-octodecylamine/ethyleneimine and the like.

SUMMARY OF THE INVENTION The present invention provides a process for the preparation of dyeable polyolefin fibers, having a high bulk, as well as the dyeable bulk fiber products obtained by this process.

It has now surprisingly been found that textile fibers dyeable with acid dyestulfs for wool and that have an increased bulkiness are obtained by mixing in ratios between. about 10:90 and about 90: 10:

6 3,501,371 Patented Mar. 17, 1970 (a) dyeable fibers comprising polyolefins consisting at least prevailingly of isotactic macromolecules which are obtained by conventional spinning operations, optional treatment with monoand di-epoxy compounds, drawing, crimping and thermal treatment of dimensional stabilization at -150 C.,

(b) dyeable fibers comprising polyolefins consisting at least prevailingly of isotactic macromolecules which are obtained by conventional pinning operations, optional treatments with monoand di-epoxy compounds, thermal treatment at 80l40 C., drawing, crimping and successive possible finishing treatments, which are carried out at temperatures not higher than 50 C.,

and then preparing the yarn according to the normal textile cycles and finally subjecting the yarn to a thermal treatment at IOU- C.

This last thermal treatment has to be carried out at a temperature not higher than the one used for the dimentional stabilization of part (a).

The dyeable polyolefin fiber used in the present invention are prepared from polyolefins consisting at least prevailingly of isotactic macromolecules obtained by spinning of polymers having an intrinsic viscosity higher than 1, having added thereto condensation products of epichlorohydrin with amine compounds.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a photograph of a fiber prepared in accordance with the present invention but before the final heat treatment; and

FIG. 2 is a photograph of a bulk fiber of the present invention, being the fiber of FIG. 1 after the final heat treatment in accordance with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The fibers of the present invention comprise the fibers obtained from polyolefins consisting at least prevailingly of isotactic macromolecules obtained by low-pressure polymerization with stereospecific catalysts.

A the polyolefin, polypropylene consisting essentially of macromolecules having isotactic structure, obtained by stereospecific polymerization of propylene, is preferably used. Crystalline polyolefins deriving from monomers of the formula R-CH:C'H2, wherein R is an alkyl or aryl group or a hydrogen atom are also suitable for use in the present invention. The polymers can be admixed with tinctorial modifiers, opacifiers, organic and inorganic dyeing pigments, stabilizers, lubricants, solid dispersing agents and the like.

The mixing of the additives with the polymers is generally carried out by simple addition to the polymer of the additives while stirring. The mixtures are granulated and then extruded with melt spinning devices through spinnerets having a length/diameter ratio higher than 1. The granulation and the spinning of the mixtures are carried out by operating in the absence of oxygen, preferably in an atmosphere of inert gases such as nitrogen. After spinning, the extruded filaments are coated with monoand di-epoxy compounds and then separated according to the above ratios in two parts (a) and (b); part (a) may be subjected to an optional thermal treatment at 80l40 C., it is then subjected to drawing with drawing ratios from about 1:2 to 1:12 (preferably from 1:2 to 1:4), at temperatures of about 80-140 C., in a drawing device heated with hot air or steam or with a similar fluid, or provided with a heating plate, and then crimped and subjected to a thermal treatment of dimensional stabilization at l00l50 C.; this stabilization by heating is carried out under free-shrinking conditions; part (b),

after spinning, must be subjected to thermal treatment at 30140 C., to drawing, crimping and to other conven- :ional finishing treatments which treatments, however, :annot be carried out at temperatures higher than 50 C. The filaments of both parts are cut into staple at the desired length and then blended according to conventional methods. After blending, the yarn is prepared by conventional technique and subjected to a thermal treatment at 100-440 C. for times up to about 90 minutes. [t is the combination of (1) the preliminary thermal treatment on part (b), (2) the lack of thermal stabilization after drawing and crimping of the fibers of part (b) (i.e. maintaining these fibers at a temperature no higher than 50 C.) and (3) the subsequent thermal treatment on the blend of parts (a) and (b) which imparts to said part (b) of the blend the increased shrinking (that amounts to about 20% at 130 C.) and the resultant bulking of the blended fiber.

The thermal treatment can be carried outwith various heated fluids such as steam, hot air and the like. It is also possible to carry out this thermal treatment on the manufactured articles instead of on the yarns.

It is preferable that the cooling down be carried out slowly. I

The blend of fibers of types (a) and (b) is made with ratios between the two types of yarns of from about -90 (ab) to 9010 (ab) and preferably from about 34-66 (ab) to 66-34 (ab).

A variant of this process, which is even more simple from the processing point of view, consists of subjecting all filaments together to the treatment with monoand di-epoxy compounds, to the thermal treatment at a temperature from 80 to 140 C., drawing, crimping, and then separating the filaments in two parts (a) and (b), of which only the part (a) is then subjected to a thermal stabilization treatment whereas part (b) does not undergo any treatment at temperatures higher than 50 C. This variant is to be regarded as a mere equivalent of the above process since it does not cause any variation in the final results. This is due to the fact that the effect of the thermal treatment carried out before drawing into filaments is nullified for the later separated filaments (a) when these, and just these, are further subjected to a thermal dimensional stabilization treatment under freeshrinking conditions. Again, in this case, it is only the separate filaments (b) that have an increased shrinking capacity, up to at 130 C.

The following examples are presented to illustrate the invention without limiting its scope.

EXAMPLE 1 A fiber was prepared by extrusion of a mixture of:

polypropylene ([1 1.3, ash content: 1 10 p.p.m., residue after heptane extraction=97%) 96.5 kg. and

epichlorohydrin-piperazine-dicyclohexylhexamethylenediamine polycondensate ([1;]=0.38, in CHCL at 0.5%) 3.5 kg.

The mixture was granulated in an extruder, under an oxygen-free atmosphere, at 230 C.

The granulate was spun with a melt spinning device under the following conditions:

Screw temperature-240 C.

Spinning head temperature-260 C.

Spinneret temperature-265 C.

Spinneret type-250 holes, whose diameter was 0.8,

length 16 mm.

Winding speed (m./minute)-600.

The fiber was treated with a 5% solution of ethylene glycol diglycidyl ether, then heated at 120 C. for 40 minutes, and then drawn in hot air at 110 C., with a draw ratio of 1:2.9, reaching a count/filament of 4.4

deniers.

After drawing, the filament was crimped.

One third of the crimped filaments were cut to a length of about 120 mm. Two thirds of the crimped filaments were subjected to dimensional stabilization at 130 C. for 30 minutes and then cut to a length of about 120 mm.

The two types of fiber were then blended sandwichwise and then carded with a wool card. The blend was then spun. Skeins, each weighing g. were manufactured and treated in a hot-air oven at 130 C. for 1 hour. They were then slowly cooled.

In addition to the receptivity to acid, metallized and disperse dyestuffs, the yarns showed also the following characteristics count: metric No. 28,000/2 (K=60) (K is the twisting coefi'lcient) bulk (cc./g.) 29.

The bulk was determined by introducing into a graduated cylinder a 20 g. skein of yarn and measuring the height reached under a pressure (exerted by a piston) of about 2 g./cm.

FIGS. 1 and 2 are photographs of the fibers before and after the treatment at 130 C. for 1 hour.

The two yarns prepared separately from each of the single components of the blend, subjected to the same final treatment at 130 C. for 1 hour to which the blend was subjected, show the following bulk values:

Type (a) yarn cc./g 22 Type (b) yarn cc./g 22 EXAMPLE 2 A fiber was prepared by extrusion of a mixture of: polypropylene ([17]=l.3, ash content p.p.m., residue after heptane extractio-n:97%) 96.5 kg. and

epichlorohydrin piperazine-dicyclohexylhexamethylenediamine polycondensate ]=l.38, in 0.5% Cl-lCl 3.5 kg.

The mix was granulated in an extruder, under an oxygen-free atmosphere, at 230 C. The granulate was spun in a melt spinning device, under the following conditions:

Screw temperature-240 C.

Spinning head temperature-260 C.

Spinneret temperature265 C.

Spinneret type-60 holes, diameter 0.8, length 16 mm. Winding speed (m./minute)--600.

The fiber was treated with a 5% solution of ethylene glycol diglycidyl ether and then treated for 1 hour at 110 C. and then drawn in hot air, at 110 C., with drawing ratios of 1:2.9, reaching a count per filament of 4.4 den.

After stretching, the fiber was crimped. Half of the crimped fibers were cut to a length of about mm. The other half were subjected to dimensional stabilization at C. for 30 minutes and then cut to a length of about 120 mm. The two types of fibers were blended in a melangeuse device and then carded with a wool card. The blend was then spun.

Skeins, each weighting 100 g., were manufactured and treated in a hot-air oven at 130 C. for 1 hour. They were then slowly cooled.

In addition to receptivity to acid, metallized and disperse dyestuffs, the yarns also showed the following characteristics:

Count-metric number 28,000/2 (K:70) Bulk (cc./g.) 27

A fiber was prepared by extrusion of a mixture of:

I polypropylene (["r ]=l.8, ash content=70 p.p.m., residue after heptane extraction=97%) 193.0 kg. and

. epichlorohydrin piperazine dicyclohexylhexamethylenediamine polycondensate ([1 ]:0.38, in 0.5% CHCl 7.0 kg.

The mixture was granulated in an extruder, under an oxygen-free atmosphere, at 230 C.

The granulate was spun with a melt spinning device under the following conditions:

Screw temperature-260 C.

Spinning head temperature280 C.

Spinneret temperature-280 C.

Spinneret type60 holes, diameter 0.8 mm., length Winding speed (m./minute)-60O The fiber was treated with a 6% solution of ethylene glycol diglycidyl ether and then drawn in hot air, at 130 C., with a drawing ratio of 1:2.5.

After drawing, the fiber was crimped.

40 kg. of the crimped fiber were cut to a length of about 120 mm. 60 kg. of the crimped fiber were, on the contrary, first subjected to a dimensional stabilization treatment at 135 C., for 60 minutes, and then cut to a length of about 90 mm.

The two types of fibers were blended sandwichwise and then carded with a wool card.

The blend was spun. Skeins, each weighting 100 g., were manufactured and placed in water at 100 C. for 1 hour, They were then removed, centrifuged and dried.

In addition to receptivity to acid, metallized and disperse dyestuffs, the yarn showed the following characteristics:

countmetric No. 15,000/3 (K=60) bulk (cc./g.)=27.

The bulk was determined as in Example 1.

The yarns consisting of the single components of the blend, subjected to the same treatment at 100 C. for 1 hour to which the blend had been subjected, showed the following bulk values:

Cc./g. Type (a) yarn 21-23 Type (b) yarn 21-23 Variations, modifications and changes can be made without departing from the spirit and scope of the invention.

Having thus described our invention, what we desire to secure by Letters Patent and hereby claim is:

1. Dyeable high bulk textile fibers comprising a polyolefin consisting at least prevailingly of isotactic macromolecules and having an intrinsic viscosity higher than 1, said polyolefin having admixed therewith, as a tinctorial modifier, from about 1-25% by weight of said polyolefin of a polycondensation product of epichlorohydrin with an amine, said fibers comprising a blend of (a) from about 10-90% by weight of fibers drawn at between about 80 to 140 C., thereafter crimped, stabilized by heating under free-shrinking conditions at a temperature of from about 100-150 C. and then cut into staple, and

(b) correspondingly, from about 90-10% by weight of fibers drawn at a temperature between about 80 to 140 C. and thereafter crimped which fibers had been subjected to a thermal treatment at a temperature of from about 80 to 140 C. before being drawn and crimped but which were not thermally stabilized after drawing and crimping, said fibers having been exposed to temperatures no higher than about 50 C. and having been cut into staple after said drawing and crimping and before blending,

said blend having been subjected to thermal treatment at a temperature of from about 100-150 C.

2. The bulk fibers of claim 1 wherein said polyolefin is polypropylene consisting at least prevailingly of isotactic macromolecules.

3. The bulk fibers of claim 2 wherein said polypropylene consists essentially of isotactic macromolecules.

4. The bulk fibers of claim 1 wherein said blend comprises from about 34-66% by weight of said stabilized fibers (a) and correspondingly, from about 66-34% by weight of said unstabilized fibers (b).

5. A process for preparing the bulk fibers of claim 1, said process comprising preparing textile fibers from a mixture of a polyolefin consisting at least prevailingly of isotactic macromolecules and from about 1-25% by weight of said polyolefin of a condensation product of epichlorohydrin with an amine; subjecting at least a portion of said fibers to a preliminary thermal treatment at a temperature of from about -140 C.; thereafter drawing at a temperature of from about 80 to 140 C. and crimping said fibers; subjecting a portion (a) of said drawn and crimped fibers, which portion of fibers may or may not have been subjected to said preliminary thermal treatment, to a dimensional stabilization treatment at a temperature of from about IOU-150 C.; maintaining another portion (b) of said drawn and crimped fibers, which portion of fibers had been subjected to said preliminary thermal treatment, at a temperature no higher than about 50 C.; cutting both said fibers (a) and (b) into staple fibers; blending from about 10-90% by weight of said stabilized staple fibers (a) with, correspondingly, about -10% by weight of said unstabilized staple fibers (-b); and subjecting the resulting fiber blend to a thermal bulking treatment at a temperature of from about -150 C., whereby to cause a differential shrinkage of said staple fibers (a) and (b) in said blend to thereby produce said bulk fibers.

6. The process of claim 5 wherein said fibers are treated with monoor di-epoxy compounds before said drawing and crimping steps.

7. The process of claim 5 wherein said polyolefin is polypropylene consisting at least prevailingly of isotactic macromolecules.

8. The process of claim 7 wherein said polypropylene consists essentially of isotactic macromolecules.

9. The process of claim 5 wherein said blend comprises from about 34-66% by weight of said stabilized fibers (a) and correspondingly, from about 66-34% by weight of said unstabilized fibers (b).

10. The process of claim 5 wherein said bulking treatment is carried out for a time up to about 90 minutes.

11. The process of claim 5 wherein said thermal bulking treatment is carried out in a hot air oven.

12. The process of claim 5 wherein said thermal bulking treatment is carried out in steam.

References Cited UNITED STATES PATENTS 3,019,507 2/1962 Maragliano et al. 161-173 3,039,171 6/1962 Hume et al.

3,245,751 4/1966 Bonvicini 855 3,288,897 11/1966 Leicht 8115.5 3,414,957 12/1968 Langstaff et al.

ROBERT F. BURNETT, Primary Examiner LINDA M. CARLIN, Assistant Examiner U.S. c1. X.R. 

